There are many types of topical antiperspirant products that are commercially available or otherwise known in the antiperspirant art. Most of these products are formulated as roll-on liquids, creams, emulsions, gels, gel-solids, or other solid stick formulations, and comprise an antiperspirant active and suspending or thickening agent incorporated into a suitable liquid carrier. These products are designed to provide effective perspiration and odor control while also being cosmetically acceptable during and after application onto the axillary area or other areas of the skin. Most of these antiperspirant products contain perfumes which help provide a pleasant fragrance during or after application of the product, or which otherwise help to hide or mask malodors associated with the use of the product.
Perfumes are generally included in antiperspirant products as free perfumes. The free perfumes are often prematurely lost due to various factors including evaporation, especially when the perfume materials are highly volatile perfumes. Therefore, many antiperspirant products are composed mainly of less volatile perfume materials in order to maximize the fragrance character during storage and use of the product. Although the fragrance character of the less volatile perfume materials is more substantive as compared to highly volatile perfumes, both perfume materials can rapidly spread and emit perfume odor impressions upon application of the antiperspirant product on the skin. The rate at which the perfume materials spread and emit fragrance in the surrounding atmosphere generally decreases after application and during use of the product, and this can result in minimal or no consumer perceived perfume odor character after a few hours and sometimes the fragrance duration of these materials is insufficient to help hide or mask perspiration malodors.
In order to extend fragrance character and to ensure greater stability of perfume materials, some antiperspirant products contain perfume inclusion complexes in addition to the free perfumes. The use of complexing agents such as cyclodextrins to stabilize perfume materials and extend fragrance character is well known, and the preparation and use of cyclodextrin inclusion complexes of perfumes and other active materials have been continually described in the art. Cyclodextrins that are typically used in antiperspirant formulations are those cyclodextrin compounds that are soluble in water and insoluble in the antiperspirant matrix to provide for sustained release of the perfume materials until the perfume/cyclodextrin complex comes in contact with water contained in human body fluid such as sweat. The speed of release of the encapsulated perfumes can be influenced by several factors including the particle size of the complex, the amount of water available, and the capacity of antiperspirant product to remain on the skin.
Some antiperspirant products have a tendency to remain on the skin of the user longer than others. Antiperspirant cream products, for example, can have more capacity in contacting the axillary area of the skin and remaining on the axilla as compared to antiperspirant stick products. The antiperspirant creams have a soft texture which allows for easy application and spreadability of the creams. It is believed that the ease of spreading provides more capacity for application of the product and this can result in greater contact between the product and the skin surface.
It has now been found that the fragrance odor impressions of encapsulated perfumes can be improved by incorporating perfume/cyclodextrin inclusion complexes into an anhydrous antiperspirant cream composition. The antiperspirant cream remains on the skin until it is washed-off, and this extended duration of the antiperspirant cream on the skin provides for extended contact of the perfume/cyclodextrin complex with the skin. The antiperspirant cream also provides a stable medium for maintaining the complex on the skin until the complex comes in contact with sweat and the cyclodextrin enclosing the perfume dissolves and releases the perfume. Therefore, the incorporation of perfume/cyclodextrin inclusion complexes in antiperspirant cream formulations provides extended contact of the complexes with the skin and sustained release of perfume materials which can result in fragrance odor impressions for extended periods after application and during use of the antiperspirant cream product. It is believed that these same release profiles are not found in other antiperspirant formulations such as solid sticks and roll-on liquids.
It is therefore an object of the present invention to provide an anhydrous antiperspirant cream composition that has improved fragrance longevity, and further to provide such a composition which contains cyclodextrin inclusion complexes of perfumes. It is a further object of the present invention to provide an anhydrous antiperspirant cream composition that contains perfume/cyclodextrin inclusion complexes that provide for sustained release of the perfumes after application of the composition and upon contact of the complex with human body fluid. It is yet another object of the present invention to provide such a composition that has low visible residue, good dry skin feel, is easy to wash off, provides good efficacy, and that remains stable over extended periods of time.